For years, we’ve all been hearing that IPv6 is the future of the Internet, along with urgings that adoption of IPv6 be fast-tracked by everyone. As we head into 2016, it’s quite surprising how little IPv6 is being utilized in production networks, and how much of that usage is stacked on top of IPv4. Or perhaps it’s not so surprising – IPv4 address space is still readily available; no one is being turned away, and the Internet is still humming along quite nicely on good old IPv4 space. Should we even care?

The IPv4 addressing scheme  allows a maximum of 4,294,967,296 possible unique addresses – and 20+ years ago it was generally believed that the world would never need anywhere near that many IP addresses. Fast-forward to modern times: as of mid-summer of 2015, ARIN (a governing body tasked with handing out IP addresses to carriers, ISPs and large end-users) has less than 50,000 IPv4 addresses left, and has entered the 4th and final phase of their IPv4 depletion countdown plan. Clearly the hunger for IP address space far exceeded the expectations of those early pioneers.

Over the last few years, providers of Internet services have been actively working on rolling out support for the next generation of IP addressing, named IPv6. The IPv6 address space is many orders of magnitude larger than the older v4 space. IPv6 addresses use eight groups of hexadecimal numbers joined by colons to express a unique address. Because IPv6 addresses are so long, a shortened notation is allowed in which consecutive groups of zero values can be summarized with a double colon. For example, fd7e:e657:486d:9bcf:0000:0000:0000:0001 can be more simply written as fd7e:e657:486d:9bcf::1. The IPv4 addressing scheme allows a mind-blowing 340,282,366,920,938,463,463,374,607,431,768,211,456 possible unique addresses. IPv6 also implements new methods designed to make it easier v6 addresses and data packets to find their way around nearby devices and the Internet at large.

IPv6 uses a subnetting scheme that is similar to the v4 scheme on the surface. Certain subnet sizes have been designated as being the default for a given entity type (i.e., “residential”, “business”, “ISP”), but as with v4, subnet sizes can be tailored to a particular need as long as technical requirements are conformed to. A table of typical IPv6 subnet sizes:

If you are wondering why a “residence” would need 18,446,744,073,709,551,616 IP addresses, you are not alone… but in any event you can see that the v6 addressing scheme is well-suited for the IP address needs of the world (and perhaps beyond) well into the future.

Adoption of v6 has been slow, but with the rapid depletion of v4 addresses mentioned earlier, v6 will become increasingly important in the near future. Perhaps nothing is driving the urgency of IPv6 adoption as much as the Internet of Things, which ensures that the world will need far more unqiue addresses than the v4 scheme could possibly handle.

The upshot of all of this is clear: make IPv6 a part of your colocation strategy now to avoid headaches later.